<template>
  <div class="btns">
    <el-button type="primary" @click="handleZoomOut">单击缩小</el-button>
    <el-button type="primary" @click="handleZoomIn">单击放大</el-button>
    <el-button type="primary" @click="handlePanToSZ">平移到【深圳】</el-button>
    <el-button type="primary" @click="handleRestore">复位</el-button>
  </div>

  <div id="map"></div>
</template>

<script lang="ts" setup>
import { onMounted, onBeforeUnmount } from 'vue'
import { Map, View } from 'ol'
import { Coordinate } from 'ol/coordinate'
import { defaults, ZoomToExtent } from 'ol/control'
import { Tile as TileLayer } from 'ol/layer'
import { XYZ } from 'ol/source'
import { MAPURL, ATTRIBUTIONS } from '../../constants'

let map: Map | null = null
//地图视图的初始参数
let view: View
let zoom: number
let center: Coordinate
let rotation: number

const raster = new TileLayer({
  source: new XYZ({
    attributions: ATTRIBUTIONS,
    url: MAPURL,
    maxZoom: 20
  })
})

const initMap = () => {
  map = new Map({
    //初始化map
    target: 'map',
    controls: defaults({
      attributionOptions: {
        collapsible: true
      }
    }).extend([
      new ZoomToExtent({
        extent: [
          // 坐标值
          813079.7791264898, 5929220.284081122, 848966.9639063801, 5936863.986909639
        ]
      })
    ]),
    //地图容器中加载的图层
    layers: [
      //加载瓦片图层数据
      raster
    ],
    view: new View({
      projection: 'EPSG:4326', // 坐标系，有EPSG:4326和EPSG:3 857
      center: [0, 0], // 深圳坐标
      //地图初始显示级别
      zoom: 5,
      //最小级别
      minZoom: 1,
      //最大级别
      maxZoom: 18,
      //设置旋转角度
      rotation: Math.PI / 6
    })
  })
  //设置地图视图的初始参数
  view = map.getView()
  zoom = view.getZoom() || 5
  center = view.getCenter() || [0, 0]
  rotation = view.getRotation()
}

// 缩小
const handleZoomOut = () => {
  if (map === null) return
  //获取地图视图
  const view = map.getView()
  //获得当前缩放级数
  const zoom = view.getZoom()
  if (zoom) {
    //地图缩小一级
    view.setZoom(zoom - 1)
  }
}

//放大
const handleZoomIn = () => {
  if (map === null) return
  //获取地图视图
  const view = map.getView()
  //获得当前缩放级数
  const zoom = view.getZoom()
  if (zoom) {
    //地图放大一级
    view.setZoom(zoom + 1)
  }
}

// 平移到深圳
const handlePanToSZ = () => {
  if (map === null) return
  //获取地图视图
  const view = map.getView()
  //平移地图
  view.setCenter([114.064839, 22.548857])
  view.setZoom(12)
}

// 复位
const handleRestore = () => {
  //初始中心点
  view.setCenter(center)
  //初始旋转角度
  view.setRotation(rotation)
  //初始缩放级数
  view.setZoom(zoom)
}

onMounted(() => {
  initMap()
})

onBeforeUnmount(() => {
  if (map) {
    map.dispose()
    map = null
  }
})
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
#map {
  width: 100%;
  height: calc(100% - 50px);
}

.btns {
  display: flex;
  justify-content: space-around;
  align-items: center;
  height: 50px;
}
</style>